| Age | Commit message (Collapse) | Author |
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While working on the patchset to remove extent locking I got a lockdep
splat with fiemap and pagefaulting with my new extent lock replacement
lock.
This deadlock exists with our normal code, we just don't have lockdep
annotations with the extent locking so we've never noticed it.
Since we're copying the fiemap extent to user space on every iteration
we have the chance of pagefaulting. Because we hold the extent lock for
the entire range we could mkwrite into a range in the file that we have
mmap'ed. This would deadlock with the following stack trace
[<0>] lock_extent+0x28d/0x2f0
[<0>] btrfs_page_mkwrite+0x273/0x8a0
[<0>] do_page_mkwrite+0x50/0xb0
[<0>] do_fault+0xc1/0x7b0
[<0>] __handle_mm_fault+0x2fa/0x460
[<0>] handle_mm_fault+0xa4/0x330
[<0>] do_user_addr_fault+0x1f4/0x800
[<0>] exc_page_fault+0x7c/0x1e0
[<0>] asm_exc_page_fault+0x26/0x30
[<0>] rep_movs_alternative+0x33/0x70
[<0>] _copy_to_user+0x49/0x70
[<0>] fiemap_fill_next_extent+0xc8/0x120
[<0>] emit_fiemap_extent+0x4d/0xa0
[<0>] extent_fiemap+0x7f8/0xad0
[<0>] btrfs_fiemap+0x49/0x80
[<0>] __x64_sys_ioctl+0x3e1/0xb50
[<0>] do_syscall_64+0x94/0x1a0
[<0>] entry_SYSCALL_64_after_hwframe+0x6e/0x76
I wrote an fstest to reproduce this deadlock without my replacement lock
and verified that the deadlock exists with our existing locking.
To fix this simply don't take the extent lock for the entire duration of
the fiemap. This is safe in general because we keep track of where we
are when we're searching the tree, so if an ordered extent updates in
the middle of our fiemap call we'll still emit the correct extents
because we know what offset we were on before.
The only place we maintain the lock is searching delalloc. Since the
delalloc stuff can change during writeback we want to lock the extent
range so we have a consistent view of delalloc at the time we're
checking to see if we need to set the delalloc flag.
With this patch applied we no longer deadlock with my testcase.
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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[BUG]
With the following file extent layout, defrag would do unnecessary IO
and result more on-disk space usage.
# mkfs.btrfs -f $dev
# mount $dev $mnt
# xfs_io -f -c "pwrite 0 40m" $mnt/foobar
# sync
# xfs_io -f -c "pwrite 40m 16k" $mnt/foobar
# sync
Above command would lead to the following file extent layout:
item 6 key (257 EXTENT_DATA 0) itemoff 15816 itemsize 53
generation 7 type 1 (regular)
extent data disk byte 298844160 nr 41943040
extent data offset 0 nr 41943040 ram 41943040
extent compression 0 (none)
item 7 key (257 EXTENT_DATA 41943040) itemoff 15763 itemsize 53
generation 8 type 1 (regular)
extent data disk byte 13631488 nr 16384
extent data offset 0 nr 16384 ram 16384
extent compression 0 (none)
Which is mostly fine. We can allow the final 16K to be merged with the
previous 40M, but it's upon the end users' preference.
But if we defrag the file using the default parameters, it would result
worse file layout:
# btrfs filesystem defrag $mnt/foobar
# sync
item 6 key (257 EXTENT_DATA 0) itemoff 15816 itemsize 53
generation 7 type 1 (regular)
extent data disk byte 298844160 nr 41943040
extent data offset 0 nr 8650752 ram 41943040
extent compression 0 (none)
item 7 key (257 EXTENT_DATA 8650752) itemoff 15763 itemsize 53
generation 9 type 1 (regular)
extent data disk byte 340787200 nr 33292288
extent data offset 0 nr 33292288 ram 33292288
extent compression 0 (none)
item 8 key (257 EXTENT_DATA 41943040) itemoff 15710 itemsize 53
generation 8 type 1 (regular)
extent data disk byte 13631488 nr 16384
extent data offset 0 nr 16384 ram 16384
extent compression 0 (none)
Note the original 40M extent is still there, but a new 32M extent is
created for no benefit at all.
[CAUSE]
There is an existing check to make sure we won't defrag a large enough
extent (the threshold is by default 32M).
But the check is using the length to the end of the extent:
range_len = em->len - (cur - em->start);
/* Skip too large extent */
if (range_len >= extent_thresh)
goto next;
This means, for the first 8MiB of the extent, the range_len is always
smaller than the default threshold, and would not be defragged.
But after the first 8MiB, the remaining part would fit the requirement,
and be defragged.
Such different behavior inside the same extent caused the above problem,
and we should avoid different defrag decision inside the same extent.
[FIX]
Instead of using @range_len, just use @em->len, so that we have a
consistent decision among the same file extent.
Now with this fix, we won't touch the extent, thus not making it any
worse.
Reported-by: Filipe Manana <fdmanana@suse.com>
Fixes: 0cb5950f3f3b ("btrfs: fix deadlock when reserving space during defrag")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Add a mechanism for named attribute_groups to hide their directory at
sysfs_update_group() time, or otherwise skip emitting the group
directory when the group is first registered. It piggybacks on
is_visible() in a similar manner as SYSFS_PREALLOC, i.e. special flags
in the upper bits of the returned mode. To use it, specify a symbol
prefix to DEFINE_SYSFS_GROUP_VISIBLE(), and then pass that same prefix
to SYSFS_GROUP_VISIBLE() when assigning the @is_visible() callback:
DEFINE_SYSFS_GROUP_VISIBLE($prefix)
struct attribute_group $prefix_group = {
.name = $name,
.is_visible = SYSFS_GROUP_VISIBLE($prefix),
};
SYSFS_GROUP_VISIBLE() expects a definition of $prefix_group_visible()
and $prefix_attr_visible(), where $prefix_group_visible() just returns
true / false and $prefix_attr_visible() behaves as normal.
The motivation for this capability is to centralize PCI device
authentication in the PCI core with a named sysfs group while keeping
that group hidden for devices and platforms that do not meet the
requirements. In a PCI topology, most devices will not support
authentication, a small subset will support just PCI CMA (Component
Measurement and Authentication), a smaller subset will support PCI CMA +
PCIe IDE (Link Integrity and Encryption), and only next generation
server hosts will start to include a platform TSM (TEE Security
Manager).
Without this capability the alternatives are:
* Check if all attributes are invisible and if so, hide the directory.
Beyond trouble getting this to work [1], this is an ABI change for
scenarios if userspace happens to depend on group visibility absent any
attributes. I.e. this new capability avoids regression since it does
not retroactively apply to existing cases.
* Publish an empty /sys/bus/pci/devices/$pdev/tsm/ directory for all PCI
devices (i.e. for the case when TSM platform support is present, but
device support is absent). Unfortunate that this will be a vestigial
empty directory in the vast majority of cases.
* Reintroduce usage of runtime calls to sysfs_{create,remove}_group()
in the PCI core. Bjorn has already indicated that he does not want to
see any growth of pci_sysfs_init() [2].
* Drop the named group and simulate a directory by prefixing all
TSM-related attributes with "tsm_". Unfortunate to not use the naming
capability of a sysfs group as intended.
In comparison, there is a small potential for regression if for some
reason an @is_visible() callback had dependencies on how many times it
was called. Additionally, it is no longer an error to update a group
that does not have its directory already present, and it is no longer a
WARN() to remove a group that was never visible.
Link: https://lore.kernel.org/all/2024012321-envious-procedure-4a58@gregkh/ [1]
Link: https://lore.kernel.org/linux-pci/20231019200110.GA1410324@bhelgaas/ [2]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/2024013028-deflator-flaring-ec62@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We need the driver core changes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Without this the kernel crashes in kfree for files with a sufficiently
large number of extents.
Fixes: d4c75a1b40cd ("xfs: convert remaining kmem_free() to kfree()")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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Eric Hong found that when using ftruncate to expand an empty file,
exfat_ent_set() will fail if discontinuous clusters are allocated.
The reason is that the empty file does not have a cluster chain,
but exfat_ent_set() attempts to append the newly allocated cluster
to the cluster chain. In addition, exfat_find_last_cluster() only
supports finding the last cluster in a non-empty file.
So this commit adds a check whether the file is empty. If the file
is empty, exfat_find_last_cluster() and exfat_ent_set() are no longer
called as they do not need to be called.
Fixes: f55c096f62f1 ("exfat: do not zero the extended part")
Reported-by: Eric Hong <erichong@qnap.com>
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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Pull bcachefs fixes from Kent Overstreet:
"Mostly pretty trivial, the user visible ones are:
- don't barf when replicas_required > replicas
- fix check_version_upgrade() so it doesn't do something nonsensical
when we're downgrading"
* tag 'bcachefs-2024-02-17' of https://evilpiepirate.org/git/bcachefs:
bcachefs: Fix missing va_end()
bcachefs: Fix check_version_upgrade()
bcachefs: Clamp replicas_required to replicas
bcachefs: fix missing endiannes conversion in sb_members
bcachefs: fix kmemleak in __bch2_read_super error handling path
bcachefs: Fix missing bch2_err_class() calls
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Pull smb client fixes from Steve French:
"Five smb3 client fixes, most also for stable:
- Two multichannel fixes (one to fix potential handle leak on retry)
- Work around possible serious data corruption (due to change in
folios in 6.3, for cases when non standard maximum write size
negotiated)
- Symlink creation fix
- Multiuser automount fix"
* tag '6.8-rc4-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
smb: Fix regression in writes when non-standard maximum write size negotiated
smb: client: handle path separator of created SMB symlinks
smb: client: set correct id, uid and cruid for multiuser automounts
cifs: update the same create_guid on replay
cifs: fix underflow in parse_server_interfaces()
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While performing the IO fault injection test, I caught the following data
corruption report:
XFS (dm-0): Internal error ltbno + ltlen > bno at line 1957 of file fs/xfs/libxfs/xfs_alloc.c. Caller xfs_free_ag_extent+0x79c/0x1130
CPU: 3 PID: 33 Comm: kworker/3:0 Not tainted 6.5.0-rc7-next-20230825-00001-g7f8666926889 #214
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
Workqueue: xfs-inodegc/dm-0 xfs_inodegc_worker
Call Trace:
<TASK>
dump_stack_lvl+0x50/0x70
xfs_corruption_error+0x134/0x150
xfs_free_ag_extent+0x7d3/0x1130
__xfs_free_extent+0x201/0x3c0
xfs_trans_free_extent+0x29b/0xa10
xfs_extent_free_finish_item+0x2a/0xb0
xfs_defer_finish_noroll+0x8d1/0x1b40
xfs_defer_finish+0x21/0x200
xfs_itruncate_extents_flags+0x1cb/0x650
xfs_free_eofblocks+0x18f/0x250
xfs_inactive+0x485/0x570
xfs_inodegc_worker+0x207/0x530
process_scheduled_works+0x24a/0xe10
worker_thread+0x5ac/0xc60
kthread+0x2cd/0x3c0
ret_from_fork+0x4a/0x80
ret_from_fork_asm+0x11/0x20
</TASK>
XFS (dm-0): Corruption detected. Unmount and run xfs_repair
After analyzing the disk image, it was found that the corruption was
triggered by the fact that extent was recorded in both inode datafork
and AGF btree blocks. After a long time of reproduction and analysis,
we found that the reason of free sapce btree corruption was that the
AGF btree was not recovered correctly.
Consider the following situation, Checkpoint A and Checkpoint B are in
the same record and share the same start LSN1, buf items of same object
(AGF btree block) is included in both Checkpoint A and Checkpoint B. If
the buf item in Checkpoint A has been recovered and updates metadata LSN
permanently, then the buf item in Checkpoint B cannot be recovered,
because log recovery skips items with a metadata LSN >= the current LSN
of the recovery item. If there is still an inode item in Checkpoint B
that records the Extent X, the Extent X will be recorded in both inode
datafork and AGF btree block after Checkpoint B is recovered. Such
transaction can be seen when allocing enxtent for inode bmap, it record
both the addition of extent to the inode extent list and the removing
extent from the AGF.
|------------Record (LSN1)------------------|---Record (LSN2)---|
|-------Checkpoint A----------|----------Checkpoint B-----------|
| Buf Item(Extent X) | Buf Item / Inode item(Extent X) |
| Extent X is freed | Extent X is allocated |
After commit 12818d24db8a ("xfs: rework log recovery to submit buffers
on LSN boundaries") was introduced, we submit buffers on lsn boundaries
during log recovery. The above problem can be avoided under normal paths,
but it's not guaranteed under abnormal paths. Consider the following
process, if an error was encountered after recover buf item in Checkpoint
A and before recover buf item in Checkpoint B, buffers that have been
added to the buffer_list will still be submitted, this violates the
submits rule on lsn boundaries. So buf item in Checkpoint B cannot be
recovered on the next mount due to current lsn of transaction equal to
metadata lsn on disk. The detailed process of the problem is as follows.
First Mount:
xlog_do_recovery_pass
error = xlog_recover_process
xlog_recover_process_data
xlog_recover_process_ophdr
xlog_recovery_process_trans
...
/* recover buf item in Checkpoint A */
xlog_recover_buf_commit_pass2
xlog_recover_do_reg_buffer
/* add buffer of agf btree block to buffer_list */
xfs_buf_delwri_queue(bp, buffer_list)
...
==> Encounter read IO error and return
/* submit buffers regardless of error */
if (!list_empty(&buffer_list))
xfs_buf_delwri_submit(&buffer_list);
<buf items of agf btree block in Checkpoint A recovery success>
Second Mount:
xlog_do_recovery_pass
error = xlog_recover_process
xlog_recover_process_data
xlog_recover_process_ophdr
xlog_recovery_process_trans
...
/* recover buf item in Checkpoint B */
xlog_recover_buf_commit_pass2
/* buffer of agf btree block wouldn't added to
buffer_list due to lsn equal to current_lsn */
if (XFS_LSN_CMP(lsn, current_lsn) >= 0)
goto out_release
<buf items of agf btree block in Checkpoint B wouldn't recovery>
In order to make sure that submits buffers on lsn boundaries in the
abnormal paths, we need to check error status before submit buffers that
have been added from the last record processed. If error status exist,
buffers in the bufffer_list should not be writen to disk.
Canceling the buffers in the buffer_list directly isn't correct, unlike
any other place where write list was canceled, these buffers has been
initialized by xfs_buf_item_init() during recovery and held by buf item,
buf items will not be released in xfs_buf_delwri_cancel(), it's not easy
to solve.
If the filesystem has been shut down, then delwri list submission will
error out all buffers on the list via IO submission/completion and do
all the correct cleanup automatically. So shutting down the filesystem
could prevents buffers in the bufffer_list from being written to disk.
Fixes: 50d5c8d8e938 ("xfs: check LSN ordering for v5 superblocks during recovery")
Signed-off-by: Long Li <leo.lilong@huawei.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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when a ifdef is used in the below manner, second one could be considered as
duplicate.
ifdef DEFINE_A
...code block...
ifdef DEFINE_A
...code block...
endif
...code block...
endif
In the xfs code two such patterns were seen. Hence removing these ifdefs.
No functional change is intended here. It only aims to improve code
readability.
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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While testing a 64k-blocksize filesystem, I noticed that xfs/709 fails
to rebuild the inode btree with a bunch of "Corruption remains"
messages. It turns out that when the inode chunk size is smaller than a
single filesystem block, no block alignments constraints are necessary
for inode chunk allocations, and sb_spino_align is zero. Hence we can
skip the check.
Fixes: dbfbf3bdf639 ("xfs: repair inode btrees")
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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Pull ceph fixes from Ilya Dryomov:
"Additional cap handling fixes from Xiubo to avoid "client isn't
responding to mclientcaps(revoke)" stalls on the MDS side"
* tag 'ceph-for-6.8-rc5' of https://github.com/ceph/ceph-client:
ceph: add ceph_cap_unlink_work to fire check_caps() immediately
ceph: always queue a writeback when revoking the Fb caps
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git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs
Pull zonefs fix from Damien Le Moal:
- Fix direct write error handling to avoid a race between failed IO
completion and the submission path itself which can result in an
invalid file size exposed to the user after the failed IO.
* tag 'zonefs-6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs:
zonefs: Improve error handling
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As for IMA, move hardcoded EVM function calls from various places in the
kernel to the LSM infrastructure, by introducing a new LSM named 'evm'
(last and always enabled like 'ima'). The order in the Makefile ensures
that 'evm' hooks are executed after 'ima' ones.
Make EVM functions as static (except for evm_inode_init_security(), which
is exported), and register them as hook implementations in init_evm_lsm().
Also move the inline functions evm_inode_remove_acl(),
evm_inode_post_remove_acl(), and evm_inode_post_set_acl() from the public
evm.h header to evm_main.c.
Unlike before (see commit to move IMA to the LSM infrastructure),
evm_inode_post_setattr(), evm_inode_post_set_acl(),
evm_inode_post_remove_acl(), and evm_inode_post_removexattr() are not
executed for private inodes.
Finally, add the LSM_ID_EVM case in lsm_list_modules_test.c
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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A few additional IMA hooks are needed to reset the cached appraisal
status, causing the file's integrity to be re-evaluated on next access.
Register these IMA-appraisal only functions separately from the rest of IMA
functions, as appraisal is a separate feature not necessarily enabled in
the kernel configuration.
Reuse the same approach as for other IMA functions, move hardcoded calls
from various places in the kernel to the LSM infrastructure. Declare the
functions as static and register them as hook implementations in
init_ima_appraise_lsm(), called by init_ima_lsm().
Also move the inline function ima_inode_remove_acl() from the public ima.h
header to ima_appraise.c.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Move hardcoded IMA function calls (not appraisal-specific functions) from
various places in the kernel to the LSM infrastructure, by introducing a
new LSM named 'ima' (at the end of the LSM list and always enabled like
'integrity').
Having IMA before EVM in the Makefile is sufficient to preserve the
relative order of the new 'ima' LSM in respect to the upcoming 'evm' LSM,
and thus the order of IMA and EVM function calls as when they were
hardcoded.
Make moved functions as static (except ima_post_key_create_or_update(),
which is not in ima_main.c), and register them as implementation of the
respective hooks in the new function init_ima_lsm().
Select CONFIG_SECURITY_PATH, to ensure that the path-based LSM hook
path_post_mknod is always available and ima_post_path_mknod() is always
executed to mark files as new, as before the move.
A slight difference is that IMA and EVM functions registered for the
inode_post_setattr, inode_post_removexattr, path_post_mknod,
inode_post_create_tmpfile, inode_post_set_acl and inode_post_remove_acl
won't be executed for private inodes. Since those inodes are supposed to be
fs-internal, they should not be of interest to IMA or EVM. The S_PRIVATE
flag is used for anonymous inodes, hugetlbfs, reiserfs xattrs, XFS scrub
and kernel-internal tmpfs files.
Conditionally register ima_post_key_create_or_update() if
CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS is enabled. Also, conditionally register
ima_kernel_module_request() if CONFIG_INTEGRITY_ASYMMETRIC_KEYS is enabled.
Finally, add the LSM_ID_IMA case in lsm_list_modules_test.c.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the inode_post_remove_acl hook.
At inode_remove_acl hook, EVM verifies the file's existing HMAC value. At
inode_post_remove_acl, EVM re-calculates the file's HMAC with the passed
POSIX ACL removed and other file metadata.
Other LSMs could similarly take some action after successful POSIX ACL
removal.
The new hook cannot return an error and cannot cause the operation to be
reverted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the inode_post_set_acl hook.
At inode_set_acl hook, EVM verifies the file's existing HMAC value. At
inode_post_set_acl, EVM re-calculates the file's HMAC based on the modified
POSIX ACL and other file metadata.
Other LSMs could similarly take some action after successful POSIX ACL
change.
The new hook cannot return an error and cannot cause the operation to be
reverted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the inode_post_create_tmpfile hook.
As temp files can be made persistent, treat new temp files like other new
files, so that the file hash is calculated and stored in the security
xattr.
LSMs could also take some action after temp files have been created.
The new hook cannot return an error and cannot cause the operation to be
canceled.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the path_post_mknod hook.
IMA-appraisal requires all existing files in policy to have a file
hash/signature stored in security.ima. An exception is made for empty files
created by mknod, by tagging them as new files.
LSMs could also take some action after files are created.
The new hook cannot return an error and cannot cause the operation to be
reverted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the file_release hook.
IMA calculates at file close the new digest of the file content and writes
it to security.ima, so that appraisal at next file access succeeds.
The new hook cannot return an error and cannot cause the operation to be
reverted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
In preparation to move IMA and EVM to the LSM infrastructure, introduce the
file_post_open hook. Also, export security_file_post_open() for NFS.
Based on policy, IMA calculates the digest of the file content and
extends the TPM with the digest, verifies the file's integrity based on
the digest, and/or includes the file digest in the audit log.
LSMs could similarly take action depending on the file content and the
access mask requested with open().
The new hook returns a value and can cause the open to be aborted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the inode_post_removexattr hook.
At inode_removexattr hook, EVM verifies the file's existing HMAC value. At
inode_post_removexattr, EVM re-calculates the file's HMAC with the passed
xattr removed and other file metadata.
Other LSMs could similarly take some action after successful xattr removal.
The new hook cannot return an error and cannot cause the operation to be
reverted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the inode_post_setattr hook.
At inode_setattr hook, EVM verifies the file's existing HMAC value. At
inode_post_setattr, EVM re-calculates the file's HMAC based on the modified
file attributes and other file metadata.
Other LSMs could similarly take some action after successful file attribute
change.
The new hook cannot return an error and cannot cause the operation to be
reverted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Change evm_inode_post_setattr() definition, so that it can be registered as
implementation of the inode_post_setattr hook (to be introduced).
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
Change ima_inode_post_setattr() definition, so that it can be registered as
implementation of the inode_post_setattr hook (to be introduced).
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
|
|
The conversion to netfs in the 6.3 kernel caused a regression when
maximum write size is set by the server to an unexpected value which is
not a multiple of 4096 (similarly if the user overrides the maximum
write size by setting mount parm "wsize", but sets it to a value that
is not a multiple of 4096). When negotiated write size is not a
multiple of 4096 the netfs code can skip the end of the final
page when doing large sequential writes, causing data corruption.
This section of code is being rewritten/removed due to a large
netfs change, but until that point (ie for the 6.3 kernel until now)
we can not support non-standard maximum write sizes.
Add a warning if a user specifies a wsize on mount that is not
a multiple of 4096 (and round down), also add a change where we
round down the maximum write size if the server negotiates a value
that is not a multiple of 4096 (we also have to check to make sure that
we do not round it down to zero).
Reported-by: R. Diez" <rdiez-2006@rd10.de>
Fixes: d08089f649a0 ("cifs: Change the I/O paths to use an iterator rather than a page list")
Suggested-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Acked-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Tested-by: Matthew Ruffell <matthew.ruffell@canonical.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Cc: stable@vger.kernel.org # v6.3+
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
Write error handling is racy and can sometime lead to the error recovery
path wrongly changing the inode size of a sequential zone file to an
incorrect value which results in garbage data being readable at the end
of a file. There are 2 problems:
1) zonefs_file_dio_write() updates a zone file write pointer offset
after issuing a direct IO with iomap_dio_rw(). This update is done
only if the IO succeed for synchronous direct writes. However, for
asynchronous direct writes, the update is done without waiting for
the IO completion so that the next asynchronous IO can be
immediately issued. However, if an asynchronous IO completes with a
failure right before the i_truncate_mutex lock protecting the update,
the update may change the value of the inode write pointer offset
that was corrected by the error path (zonefs_io_error() function).
2) zonefs_io_error() is called when a read or write error occurs. This
function executes a report zone operation using the callback function
zonefs_io_error_cb(), which does all the error recovery handling
based on the current zone condition, write pointer position and
according to the mount options being used. However, depending on the
zoned device being used, a report zone callback may be executed in a
context that is different from the context of __zonefs_io_error(). As
a result, zonefs_io_error_cb() may be executed without the inode
truncate mutex lock held, which can lead to invalid error processing.
Fix both problems as follows:
- Problem 1: Perform the inode write pointer offset update before a
direct write is issued with iomap_dio_rw(). This is safe to do as
partial direct writes are not supported (IOMAP_DIO_PARTIAL is not
set) and any failed IO will trigger the execution of zonefs_io_error()
which will correct the inode write pointer offset to reflect the
current state of the one on the device.
- Problem 2: Change zonefs_io_error_cb() into zonefs_handle_io_error()
and call this function directly from __zonefs_io_error() after
obtaining the zone information using blkdev_report_zones() with a
simple callback function that copies to a local stack variable the
struct blk_zone obtained from the device. This ensures that error
handling is performed holding the inode truncate mutex.
This change also simplifies error handling for conventional zone files
by bypassing the execution of report zones entirely. This is safe to
do because the condition of conventional zones cannot be read-only or
offline and conventional zone files are always fully mapped with a
constant file size.
Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: 8dcc1a9d90c1 ("fs: New zonefs file system")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
|
|
Cross-merge networking fixes after downstream PR.
No conflicts.
Adjacent changes:
net/core/dev.c
9f30831390ed ("net: add rcu safety to rtnl_prop_list_size()")
723de3ebef03 ("net: free altname using an RCU callback")
net/unix/garbage.c
11498715f266 ("af_unix: Remove io_uring code for GC.")
25236c91b5ab ("af_unix: Fix task hung while purging oob_skb in GC.")
drivers/net/ethernet/renesas/ravb_main.c
ed4adc07207d ("net: ravb: Count packets instead of descriptors in GbEth RX path"
)
c2da9408579d ("ravb: Add Rx checksum offload support for GbEth")
net/mptcp/protocol.c
bdd70eb68913 ("mptcp: drop the push_pending field")
28e5c1380506 ("mptcp: annotate lockless accesses around read-mostly fields")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"A few regular fixes and one fix for space reservation regression since
6.7 that users have been reporting:
- fix over-reservation of metadata chunks due to not keeping proper
balance between global block reserve and delayed refs reserve; in
practice this leaves behind empty metadata block groups, the
workaround is to reclaim them by using the '-musage=1' balance
filter
- other space reservation fixes:
- do not delete unused block group if it may be used soon
- do not reserve space for checksums for NOCOW files
- fix extent map assertion failure when writing out free space inode
- reject encoded write if inode has nodatasum flag set
- fix chunk map leak when loading block group zone info"
* tag 'for-6.8-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: don't refill whole delayed refs block reserve when starting transaction
btrfs: zoned: fix chunk map leak when loading block group zone info
btrfs: reject encoded write if inode has nodatasum flag set
btrfs: don't reserve space for checksums when writing to nocow files
btrfs: add new unused block groups to the list of unused block groups
btrfs: do not delete unused block group if it may be used soon
btrfs: add and use helper to check if block group is used
btrfs: don't drop extent_map for free space inode on write error
|
|
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
|
|
The flags were set to SLAB_RED_ZONE when CONFIG_DEBUG_SLAB was enabled.
With SLAB gone, this is now dead code so remove it. With SLUB, debugging
options including red zoning can be set for orangefs caches by the
slab_debug boot parameter.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
|
|
Add an ioctl for getting and setting epoll_params. User programs can use
this ioctl to get and set the busy poll usec time, packet budget, and
prefer busy poll params for a specific epoll context.
Parameters are limited:
- busy_poll_usecs is limited to <= s32_max
- busy_poll_budget is limited to <= NAPI_POLL_WEIGHT by unprivileged
users (!capable(CAP_NET_ADMIN))
- prefer_busy_poll must be 0 or 1
- __pad must be 0
Signed-off-by: Joe Damato <jdamato@fastly.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
When using epoll-based busy poll, the prefer_busy_poll option is hardcoded
to false. Users may want to enable prefer_busy_poll to be used in
conjunction with gro_flush_timeout and defer_hard_irqs_count to keep device
IRQs masked.
Other busy poll methods allow enabling or disabling prefer busy poll via
SO_PREFER_BUSY_POLL, but epoll-based busy polling uses a hardcoded value.
Fix this edge case by adding support for a per-epoll context
prefer_busy_poll option. The default is false, as it was hardcoded before
this change.
Signed-off-by: Joe Damato <jdamato@fastly.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
When using epoll-based busy poll, the packet budget is hardcoded to
BUSY_POLL_BUDGET (8). Users may desire larger busy poll budgets, which
can potentially increase throughput when busy polling under high network
load.
Other busy poll methods allow setting the busy poll budget via
SO_BUSY_POLL_BUDGET, but epoll-based busy polling uses a hardcoded
value.
Fix this edge case by adding support for a per-epoll context busy poll
packet budget. If not specified, the default value (BUSY_POLL_BUDGET) is
used.
Signed-off-by: Joe Damato <jdamato@fastly.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Allow busy polling on a per-epoll context basis. The per-epoll context
usec timeout value is preferred, but the pre-existing system wide sysctl
value is still supported if it specified.
busy_poll_usecs is a u32, but in a follow up patch the ioctl provided to
the user only allows setting a value from 0 to S32_MAX.
Signed-off-by: Joe Damato <jdamato@fastly.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Convert the zonefs filesystem to use the new mount API.
Tested using the zonefs test suite from:
https://github.com/damien-lemoal/zonefs-tools
Signed-off-by: Bill O'Donnell <bodonnel@redhat.com>
Reviewed-by: Ian Kent <raven@themaw.net>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
|
|
Fixes: https://lore.kernel.org/linux-bcachefs/202402131603.E953E2CF@keescook/T/#u
Reported-by: coverity scan
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
|
|
When also downgrading, check_version_upgrade() could pick a new version
greater than the latest supported version.
Fixes:
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
|
|
This prevents going emergency read only when the user has specified
replicas_required > replicas.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
|
|
Since commit 28270e25c69a ("btrfs: always reserve space for delayed refs
when starting transaction") we started not only to reserve metadata space
for the delayed refs a caller of btrfs_start_transaction() might generate
but also to try to fully refill the delayed refs block reserve, because
there are several case where we generate delayed refs and haven't reserved
space for them, relying on the global block reserve. Relying too much on
the global block reserve is not always safe, and can result in hitting
-ENOSPC during transaction commits or worst, in rare cases, being unable
to mount a filesystem that needs to do orphan cleanup or anything that
requires modifying the filesystem during mount, and has no more
unallocated space and the metadata space is nearly full. This was
explained in detail in that commit's change log.
However the gap between the reserved amount and the size of the delayed
refs block reserve can be huge, so attempting to reserve space for such
a gap can result in allocating many metadata block groups that end up
not being used. After a recent patch, with the subject:
"btrfs: add new unused block groups to the list of unused block groups"
We started to add new block groups that are unused to the list of unused
block groups, to avoid having them around for a very long time in case
they are never used, because a block group is only added to the list of
unused block groups when we deallocate the last extent or when mounting
the filesystem and the block group has 0 bytes used. This is not a problem
introduced by the commit mentioned earlier, it always existed as our
metadata space reservations are, most of the time, pessimistic and end up
not using all the space they reserved, so we can occasionally end up with
one or two unused metadata block groups for a long period. However after
that commit mentioned earlier, we are just more pessimistic in the
metadata space reservations when starting a transaction and therefore the
issue is more likely to happen.
This however is not always enough because we might create unused metadata
block groups when reserving metadata space at a high rate if there's
always a gap in the delayed refs block reserve and the cleaner kthread
isn't triggered often enough or is busy with other work (running delayed
iputs, cleaning deleted roots, etc), not to mention the block group's
allocated space is only usable for a new block group after the transaction
used to remove it is committed.
A user reported that he's getting a lot of allocated metadata block groups
but the usage percentage of metadata space was very low compared to the
total allocated space, specially after running a series of block group
relocations.
So for now stop trying to refill the gap in the delayed refs block reserve
and reserve space only for the delayed refs we are expected to generate
when starting a transaction.
CC: stable@vger.kernel.org # 6.7+
Reported-by: Ivan Shapovalov <intelfx@intelfx.name>
Link: https://lore.kernel.org/linux-btrfs/9cdbf0ca9cdda1b4c84e15e548af7d7f9f926382.camel@intelfx.name/
Link: https://lore.kernel.org/linux-btrfs/CAL3q7H6802ayLHUJFztzZAVzBLJAGdFx=6FHNNy87+obZXXZpQ@mail.gmail.com/
Tested-by: Ivan Shapovalov <intelfx@intelfx.name>
Reported-by: Heddxh <g311571057@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CAE93xANEby6RezOD=zcofENYZOT-wpYygJyauyUAZkLv6XVFOA@mail.gmail.com/
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
At btrfs_load_block_group_zone_info() we never drop a reference on the
chunk map we have looked up, therefore leaking a reference on it. So
add the missing btrfs_free_chunk_map() at the end of the function.
Fixes: 7dc66abb5a47 ("btrfs: use a dedicated data structure for chunk maps")
Reported-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Currently we allow an encoded write against inodes that have the NODATASUM
flag set, either because they are NOCOW files or they were created while
the filesystem was mounted with "-o nodatasum". This results in having
compressed extents without corresponding checksums, which is a filesystem
inconsistency reported by 'btrfs check'.
For example, running btrfs/281 with MOUNT_OPTIONS="-o nodatacow" triggers
this and 'btrfs check' errors out with:
[1/7] checking root items
[2/7] checking extents
[3/7] checking free space tree
[4/7] checking fs roots
root 256 inode 257 errors 1040, bad file extent, some csum missing
root 256 inode 258 errors 1040, bad file extent, some csum missing
ERROR: errors found in fs roots
(...)
So reject encoded writes if the target inode has NODATASUM set.
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Currently when doing a write to a file we always reserve metadata space
for inserting data checksums. However we don't need to do it if we have
a nodatacow file (-o nodatacow mount option or chattr +C) or if checksums
are disabled (-o nodatasum mount option), as in that case we are only
adding unnecessary pressure to metadata reservations.
For example on x86_64, with the default node size of 16K, a 4K buffered
write into a nodatacow file is reserving 655360 bytes of metadata space,
as it's accounting for checksums. After this change, which stops reserving
space for checksums if we have a nodatacow file or checksums are disabled,
we only need to reserve 393216 bytes of metadata.
CC: stable@vger.kernel.org # 6.1+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Noticed by inspection, simple factoring allows the same allocation
routine to be used for both transaction and recovery contexts.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
|
|
These few remaining GFP_NOFS callers do not need to use GFP_NOFS at
all. They are only called from a non-transactional context or cannot
be accessed from memory reclaim due to other constraints. Hence they
can just use GFP_KERNEL.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
|
|
This is core code that needs to run in low memory conditions and
can be triggered from memory reclaim. While it runs in a workqueue,
it really shouldn't be recursing back into the filesystem during
any memory allocation it needs to function.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
|
|
When recovery starts processing intents, all of the initial intent
allocations are done outside of transaction contexts. That means
they need to specifically use GFP_NOFS as we do not want memory
reclaim to attempt to run direct reclaim of filesystem objects while
we have lots of objects added into deferred operations.
Rather than use GFP_NOFS for these specific allocations, just place
the entire intent recovery process under NOFS context and we can
then just use GFP_KERNEL for these allocations.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
|
|
When running in a transaction context, memory allocations are scoped
to GFP_NOFS. Hence we don't need to use GFP_NOFS contexts in pure
transaction context allocations - GFP_KERNEL will automatically get
converted to GFP_NOFS as appropriate.
Go through the code and convert all the obvious GFP_NOFS allocations
in transaction context to use GFP_KERNEL. This further reduces the
explicit use of GFP_NOFS in XFS.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
|
|
In the past we've had problems with lockdep false positives stemming
from inode locking occurring in memory reclaim contexts (e.g. from
superblock shrinkers). Lockdep doesn't know that inodes access from
above memory reclaim cannot be accessed from below memory reclaim
(and vice versa) but there has never been a good solution to solving
this problem with lockdep annotations.
This situation isn't unique to inode locks - buffers are also locked
above and below memory reclaim, and we have to maintain lock
ordering for them - and against inodes - appropriately. IOWs, the
same code paths and locks are taken both above and below memory
reclaim and so we always need to make sure the lock orders are
consistent. We are spared the lockdep problems this might cause
by the fact that semaphores and bit locks aren't covered by lockdep.
In general, this sort of lockdep false positive detection is cause
by code that runs GFP_KERNEL memory allocation with an actively
referenced inode locked. When it is run from a transaction, memory
allocation is automatically GFP_NOFS, so we don't have reclaim
recursion issues. So in the places where we do memory allocation
with inodes locked outside of a transaction, we have explicitly set
them to use GFP_NOFS allocations to prevent lockdep false positives
from being reported if the allocation dips into direct memory
reclaim.
More recently, __GFP_NOLOCKDEP was added to the memory allocation
flags to tell lockdep not to track that particular allocation for
the purposes of reclaim recursion detection. This is a much better
way of preventing false positives - it allows us to use GFP_KERNEL
context outside of transactions, and allows direct memory reclaim to
proceed normally without throwing out false positive deadlock
warnings.
The obvious places that lock inodes and do memory allocation are the
lookup paths and inode extent list initialisation. These occur in
non-transactional GFP_KERNEL contexts, and so can run direct reclaim
and lock inodes.
This patch makes a first path through all the explicit GFP_NOFS
allocations in XFS and converts the obvious ones to GFP_KERNEL |
__GFP_NOLOCKDEP as a first step towards removing explicit GFP_NOFS
allocations from the XFS code.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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